Discovery of a new species of Adder’s tongue fern from India with comparative analysis of morphological and molecular attributes

Eusporangiate fern genus Ophioglossum L. is commonly known as Adder’s tongue fern as its fertile frond gives the appearance of snake tongue. A new species in this fern genus, O. trilokinathii belonging to Ophioglossaceae family has been discovered from the plateau region of Rajasthan State of northwestern India. The new species can be distinguished from other taxa of this genus by its smaller habit, subglobose-tuberous rhizome, basipetal emergence of young roots, aggregation of old decaying roots on rhizome apex, fertile stalk as well as spike short and thick, trophophylls in rosette, ovate or orbicular and a unique sporoderm sculpture pattern under SEM having broad reticulations with thick and raised muri enclosing large hexagonal or irregular areas on the distal and proximal faces of the spores hitherto unreported in any of the presently known taxa of Ophioglossum. In addition, comparative study of stomatal structure, foliar anatomy and nucleotide sequence data of its three chloroplast DNA markers (trnL-F, rbcL and psbA-trnH) was carried out. In view of all the attributes including habitat, ecology, morphology, foliar anatomy, stomatal features, palynology and molecular phylogenetic data, the present study suggests that the Ophioglossum specimen collected from plateau region of Rajasthan represents a hitherto undescribed species thereby warranting its establishment as O. trilokinathii sp. nov. A detailed comparative account of the new taxon with its allied species has also been provided.

Cytogenetic evidence for a new genus of Triticeae (Poaceae) endemic to the Iberian Peninsula: description and comparison with related genera

Thinopyrum curvifolium, a halo-gypsophyte endemic to the Iberian Peninsula, has an uncertain cytogenetic composition. Moreover, it is often confused with other species of the genus due to morphological resemblance. In this study, we analyse its genomic composition using in situ hybridization and study lodicule morphology and foliar anatomy, to identify distinguishing traits of the species in comparison with the remaining representatives of Thinopyrum in the Iberian Peninsula and the Balearic Islands. In situ hybridization data support the genomic formula 2n = 4x = 28, EbP. Lodicule morphology and foliar anatomy proved helpful in characterizing the species. These new discoveries, in addition to the macromorphological data compiled, support the contentions that (1) T. curvifolium should be segregated from Thinopyrum sensu D.R.Dewey, and (2) a new cytogenetically based genus should be proposed in order to classify the species properly according to the cytogenetically based criteria traditionally proposed for the classification of Triticeae. Therefore, we hereby propose a new genus named Pauneroa gen. nov., including the new nomenclatural combination Pauneroa curvifolia comb. nov., and provide a detailed iconography of the plant, macroscopically comparing the genus with closely related genera.

Foliar anatomy of Rhynchosia spp. (Leguminosae, Papilionoideae) from Roraima state, northern Brazilian Amazon

ABSTRACT Comparative studies on the structure of foliar anatomy in four species of Rhynchosia from Roraima state (northern Brazilian Amazon) were carried out to identify additional morphological characters to support the definition of the systematic boundaries among the species. Fully expanded leaves, including the petioles, were collected from the upper nodes of a plant’s stem. Anatomical characters were observed in cross-sections of the middle portion of leaflets and petiole segments. Presence and distribution of glandular trichomes, continuity of sclerenchyma around the vascular bundles in leaflet blades and the conformation of the area between the two ridges of petioles were important characters to distinguish among the species of Rhynchosia. For the first time we report a distinct multicellular gland-like structure which we found in the petioles of three species.

A new species of Dichaea (Orchidaceae) from Brazil with special reference to its foliar anatomy

A new Dichaea species is described. It shows an ovate an ovate, non-clawed lip, a feature up to now never observed in the genus that separates it from all related species. The species has been observed only in the Central Amazon.